Sähköhiilet

Sähköhiilet, often translated as carbon brushes, are crucial components in many electric motors and generators. They are essentially conductive blocks, typically made of carbon or a composite material, that serve to transfer electrical current between stationary and rotating parts. This contact is essential for the operation of devices that rely on the principle of electromagnetic induction.

The primary function of a sähköhiili is to maintain continuous electrical contact as a rotor spins. This is achieved by the brushes being spring-loaded against a commutator or slip ring assembly. The commutator is a segmented part of the rotor in DC motors, and the brushes facilitate the reversal of current direction in the armature coils as they rotate, ensuring continuous torque. In AC motors, slip rings are used, and the brushes transfer current to or from the rotor windings.

The materials used for sähköhiilet are carefully chosen for their electrical conductivity, mechanical strength, and ability to withstand friction and heat. Pure carbon is common, but it can be mixed with other elements like copper, silver, or graphite to enhance conductivity or reduce wear. The wear rate of sähköhiilet is a factor in their lifespan; they are consumable parts that gradually wear down over time and require replacement. Proper maintenance and selection of the correct type of sähköhiili are vital for the efficiency and longevity of the electrical machinery they are a part of.